Ocular manifestations of syphilis are protean and may affect all structures, including conjunctiva, sclera, cornea, lens, uveal tract, retina, optic nerve, cranial nerves, and pupillomotor pathways. Patients present with pain, redness, photophobia, blurred vision, and floaters. Intraocular inflammation may be granulomatous or nongranulomatous, unilateral or bilateral, and it may affect the anterior or posterior segment. Anterior segment findings can include iris roseola, vascularized papules (iris papulosa), larger red nodules (iris nodosa), and gummata. Interstitial keratitis, posterior synechiae, lens dislocation, and iris atrophy can also occur.
Posterior segment findings of acquired syphilis include vitritis, chorioretinitis, focal/multifocal retinitis, necrotizing retinochoroiditis, retinal vasculitis, exudative retinal detachment, isolated papillitis, and neuroretinitis. A focal or multifocal chorioretinitis, usually associated with a variable degree of vitritis, is the most common manifestation (Fig 10-2). These lesions are typically small, grayish yellow, and located in the postequatorial fundus, but they may become confluent. Retinal vasculitis and disc edema, with exudates appearing around the disc and the retinal arterioles, together with serous retinal detachment, may accompany the chorioretinitis. A syphilitic posterior placoid chorioretinitis has been described, the clinical appearance and angiographic characteristics of which are thought to be pathognomonic of secondary syphilis (Fig 10-3 and Video 10-1). Solitary or multifocal, macular or papillary, placoid, yellowish gray lesions at the level of the RPE, often with accompanying vitritis, display corresponding early hypofluorescence and late staining, along with retinal perivenous staining on fluorescein angiography (FA). Indocyanine green (ICG) angiography shows hypofluorescent spots corresponding to the lesions. Optical coherence tomography (OCT) displays irregularities at the level of the RPE, with corresponding disorganization of outer retinal layers.
Less common posterior segment involvement includes focal retinitis, periphlebitis, and, infrequently, exudative retinal detachment. Syphilis may present as a focal retinitis (Fig 10-4) or as a peripheral necrotizing retinochoroiditis that may resemble acute retinal necrosis or progressive outer retinal necrosis. Punctate inner retinal infiltrates have also been described (Fig 10-5). Although the foci of retinitis may become confluent and are frequently associated with retinal vasculitis, syphilitic retinitis is more slowly progressive and responds dramatically to therapy with intravenous penicillin, often with a good visual outcome. Isolated retinal vasculitis that affects the retinal arterioles, capillaries, and larger arteries or veins (or both) is another feature of syphilitic intraocular inflammation that may best be appreciated on FA. Focal retinal vasculitis may masquerade as a branch retinal vein and/or arterial occlusion.
Figure 10-2 Syphilitic chorioretinitis. A, Fundus photograph of acute syphilitic chorioretinitis. Note diffuse edema of the disc, retina, and choroid in the posterior pole. B, Fundus photograph showing healing chorioretinitis after 2 weeks of intravenous penicillin therapy. Note the subretinal hard exudate that is organizing, as well as the reduction in disc edema and choroidal inflammation.
(Courtesy of Ramana S. Moorthy, MD.)
Figure 10-3 Fundus (top left), angiographic (top middle and top right), and optical coherence tomography (bottom) features of syphilitic posterior placoid chorioretinitis. Progressive placoid hyperfluorescence is seen on angiography (top right), in correspondence to the yellowish geographic infiltrate in the posterior pole (top left). Spectral-domain optical coherence tomography reveals deep granular changes, with disruption of outer retinal layers and underlying homogeneous hyper-reflectivity of the inner choroid.
(Courtesy of Daniel V. Vasconcelos-Santos, MD, PhD.)
SD-OCT of syphilitic posterior placoid chorioretinitis.
Courtesy of Daniel V. Vasconcelos-Santos, MD, PhD.
Access the video at www.aao.org/bcscvideo_section09.
Syphilis is an important entity to consider in the differential diagnosis of patients with neuroretinitis and papillitis who present with macular star formation. Patients with syphilis who are immunocompromised or who have an HIV infection or AIDS may have atypical or more fulminant ocular disease patterns. Optic neuritis and neuroretinitis are more common in the initial presentation of these patients, and disease recurrences may be noted even after appropriate antibacterial therapy.
Neuro-ophthalmic manifestations of syphilis include the Argyll Robertson pupil, ocular motor nerve palsies, optic neuropathy, and retrobulbar optic neuritis, all of which appear most often in patients with tertiary syphilis or in neurosyphilis (see BCSC Section 5, Neuro-Ophthalmology, for further discussion).
Figure 10-4 Fundus photograph of acute syphilitic retinitis.
Figure 10-5 Fundus photograph of the right eye of a patient with syphilitic posterior uveitis, disclosing punctate inner retinal infiltrates overlying an area of retinal edema superonasally.
(Courtesy of Daniel V. Vasconcelos-Santos, MD, PhD.)
Excerpted from BCSC 2020-2021 series: Section 9 - Uveitis and Ocular Inflammation. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.